The present invention relates to a liquid container for storing liquid to be supplied to a liquid consuming apparatus such as an ink-jet recording apparatus.
As a typical example of a conventional liquid consuming apparatus, there is a liquid ejecting apparatus which ejects a liquid droplet from an ejecting head, and as a typical example of the liquid ejecting apparatus, there is an ink-jet recording apparatus provided with an ink-jet recording head for image recording. Other liquid ejecting apparatuses include, for example, an apparatus provided with a color material ejecting head used for manufacture of a color filter of a liquid crystal display or the like, an apparatus provided with an electrode material (conductive paste) ejecting head used for electrode formation of an organic EL display, a surface emitting display (FED) or the like, an apparatus provided with a biological organic material ejecting head used for manufacture of a biochip, an apparatus provided with a sample ejecting head as a precision pipette, and the like.
The ink-jet recording apparatus as the typical example of the liquid ejecting apparatus has been recently used in many printings including color printings because noises at the time of printing are relatively low and small dots can be formed at high density.
As a supplying method of liquid to the liquid consuming apparatus typified by the ink-jet recording apparatus, there is a method in which liquid is supplied from a liquid container storing the liquid to the liquid consuming apparatus. In this method, in order that a user can easily exchange the liquid container at the point of time when the liquid in the liquid container is consumed, the liquid container is generally constructed as a cartridge which is constructed to be removably attached to the liquid consuming apparatus.
As a conventional example of such a cartridge type liquid container, there is a type in which compressed air is sent into the inside of the liquid container to pressurize the liquid in the liquid container, and the liquid in the liquid container is delivered to the outside of the cartridge by using this pressure and is supplied to the liquid consuming apparatus. As stated above, by pressurizing the liquid in the liquid container and supplying it to the liquid consuming apparatus, for example, even in the case where a liquid discharge part in the liquid consuming apparatus is higher than the position of the liquid container, or even in the case where flow path resistance from the liquid container to the liquid discharge part is high, the liquid can be stably supplied from the liquid container to the liquid discharge part.
(1) U.S. Pat. No. 6,290,343 discloses an ink cartridge of a type in which compressed air is sent into an inner flexible bag, and an ink-jet printer in which the ink cartridge is mounted. A pressure sensor is connected to a pressurizing pump for pressurizing the air. The pressurizing pump is controlled in accordance with the output of this pressure sensor so that the supply of ink is controlled.
As described above, in the ink cartridge and the ink-jet printer disclosed in U.S. Pat. No. 6,290,343, the supply of the ink is controlled on the basis of the operation of the pressurizing pump. Thus, for example, even in the case where the mounting of the ink cartridge to the ink-jet printer is poor, and the ink is not actually supplied to the inkjet printer although the pressurizing pump is operated, as long as the operation of the pressurizing pump is detected by the pressure sensor, it is mistaken that the ink is being supplied.
The present invention has been made in view of the foregoing circumstances, and has an object to provide a liquid container which is constructed such that pressurized fluid is sent into the inside of the liquid container so that liquid in the inside of the container is delivered to the outside, and in which it is possible to judge whether or not the liquid in the inside of the liquid container is actually being pressurized by the pressurized fluid.
(2) As a method of detecting an amount of ink remaining in an ink cartridge constructed to discharge ink using a pressurized fluid fed from outside, generally using air pressure, a method is disclosed in U.S. Pat. No. 6,151,039 in which electrodes are mounted on an ink bag formed of a flexible material for containing ink so as to face to each other for detecting the thickness of the ink bag. Another method is disclosed in U.S. Pat. No. 6,435,638 in which a through hole is provided in the midway of a channel for connecting an ink bag to an ink feeding port and a pressure sensor is fixed so as to seal the through hole for detecting delivery pressure by the pressure sensor.
In the ink cartridges provided with the function of detecting the amount of remaining ink, the former can continuously detect the variation in the amount of ink in relation to detecting the thickness of the ink bag, but has a problem of low detection accuracy at ink end.
On the other hand, the latter can detect the amount of ink remaining at high accuracy when the amount of ink is really small. However, the latter is difficult to detect the amount of ink before the remaining ink amount reaches a set amount, such as ink end, because it detects the pressure of ink in the ink channel. Further, the latter suffers from a problem that the amount of ink for printing is significantly small after ink end is detected and thus printing becomes impossible.
The invention has been made in view of the problems. The object is to provide a liquid container capable of accurately detecting the point in time when an amount of liquid contained therein is reduced equal to or below a set amount and capable of feeding liquid with some margin after the set amount is detected.
(3) In a conventional ink cartridge in which compressed air is introduced into the inside of a container and ink is delivered to the outside of the container by its pressure, an assembling operation for forming a sealing structure between a pressurizing chamber into which the compressed air is introduced and a reservoir chamber in which the ink is stored or a disassembling operation has been complicated.
Besides, in the conventional ink cartridge of the foregoing type, even if an attempt is made to recycle a part of the components after use, it is structurally difficult to remove only necessary components, and the recycling has been very difficult or impossible.
Further, in the conventional ink cartridge of the foregoing type, there has been a problem that the compressed air introduced into the inside of the ink cartridge permeates through a flexible film separating the ink from the compressed air and dissolves in the ink, and the print quality is lowered.
The invention has been made in view of the above circumstances, and has an object to facilitate the assembling and disassembling operation of a liquid container constructed such that pressurized fluid is sent into the inside of the liquid container so that liquid in the inside of the container is delivered to the outside.
Besides, in the liquid container of the foregoing type, the invention has an object to realize a structure which is easy to recycle.
Further, in the liquid container of the foregoing type, the invention has an object to prevent the pressurized fluid introduced into the inside of the container from dissolving in the liquid.
(4) In general, in a conventional ink cartridge provided with a detection unit of a remaining amount of ink, the ink cartridge and an ink-jet recording apparatus are connected with each other through an electric contact, an output signal of the detection unit is transmitted from the ink cartridge side to the ink-jet recording apparatus side through this electric contact, and the supply of electric power to the detection unit is also performed through the electric contact.
The detection unit of the remaining amount of ink in the conventional ink cartridge includes a type in which an actuator disposed to be adjacent to ink is vibrated and the existence of the ink is detected from its vibration state, and a type in which a light emitting element and a light receiving element are provided and the existence of the ink therebetween is detected. In any type, since electric power consumed to drive the detection unit is large, sufficient electric power can not be supplied by the supply of electric power according to a noncontact form, and as described above, the supply of electric power according to a contact form using the electric contact must be adopted.
However, in the conventional ink cartridge using the electric contact, there is a case where the electric contact causes poor contact due to the poor mounting of the ink cartridge to the ink-jet recording apparatus or the attachment of a foreign matter to the electric contact. When the poor contact occurs at the electric contact as stated above, the output of the detection unit of the remaining amount of ink is not transmitted to the ink-jet recording apparatus side, or the operation of the detection unit becomes impossible since the supply of electric power to the detection unit can not be performed, and there has been possibility that the detection of the remaining amount of ink becomes impossible, and poor printing is caused.
This invention has been made in view of the above circumstances, and has an object to provide a liquid container which can transmit information relating to a remaining amount of liquid to a liquid consuming apparatus without providing an electric contact between the liquid container and the liquid consuming apparatus.
(5) In the case where a detection unit for detecting the remaining amount of ink in the inside of a liquid container, and a unit for communicating an output signal of the detection unit without providing an electric contact (for example, a unit for performing communication by an electric wave) are provided, it is preferable that the detection unit is incorporated in the inside of the liquid container and the communication unit is also incorporated in the inside of the liquid container from the viewpoint of protection of the communication unit.
However, since a mounting space of the detection unit and the communication unit in the inside of the liquid container is limited, it is desired that while the space efficiency is considered, the detection unit and the communication unit are incorporated in the inside of the liquid container, and electrical connection of both is achieved without fail.
In addition to the case where the whole of the communication unit is disposed in the inside of the liquid container, this is also desired in the case where a part (for example, an antenna) of the communication unit is disposed at the outside of the liquid container, and the other part (for example, an electrical connection part to the detection unit, or a control part for controlling the communication) of the communication unit is disposed in the inside of the liquid container, or in the case where a communication unit is a contact type communication unit using an electric contact, a part (for example, the electric contact) of the communication unit is disposed at the outside of the liquid container, and the other part (for example, an electrical connection part to the detection unit or a control part for controlling the communication) is disposed in the inside of the liquid container.
This invention has been made in view of the above circumstances, and has an object to provide a liquid container in which when at least a part of the detection unit of the remaining amount of liquid and the communication unit is incorporated in the inside of the liquid container, electrical connection of both can be easily and certainly achieved.
(6) A liquid container in which liquid in the inside of a liquid container is pressurized by pressurized fluid is generally provided with a valve unit. That is, the liquid container as stated above is constructed such that the valve unit is provided at a liquid delivery port for delivering the liquid in the inside, and this valve unit keeps a valve closed state at a normal time, and when the liquid container is mounted in a liquid consuming apparatus, the valve is opened.
However, the valve unit in the liquid container has a problem that when the valve body is pressed from the outside in a state where the liquid container is not mounted in the liquid consuming apparatus, air flows into the inside of the liquid container, or the liquid in the inside of the liquid container leaks to the outside.
As a measure to prevent the inflow of the air, it is conceivable to provide a check valve which is opened only in the direction of delivering the liquid. However, there is a problem that this measure increases the number of parts, and the layout of part arrangement becomes difficult. Further, even if the check valve is provided as the air inflow preventing measure, the problem of the leakage of the liquid from the liquid container by pressing the valve body from the outside is not resolved.
This invention has been made in view of the above circumstances, and has an object to prevent, in a liquid container constructed such that pressurized fluid is introduced into the inside of the liquid container so that liquid in the inside of the container is delivered to the outside, the inflow of air to the inside of the liquid container and the leakage of the liquid from the liquid container.